rate-limiter
Rate Limiter
原文：https://echo.labstack.com/docs/middleware/rate-limiter
RateLimiter provides a Rate Limiter middleware for limiting the amount of requests to the server from a particular IP or id within a time period.
By default an in-memory store is used for keeping track of requests. The default in-memory implementation is focused on correctness and may not be the best option for a high number of concurrent requests or a large number of different identifiers (>16k).
Usage
To add a rate limit to your application simply add the RateLimiter middleware. The example below will limit the application to 20 requests/sec using the default in-memory store:
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| e.Use(middleware.RateLimiter(middleware.NewRateLimiterMemoryStore(20)))
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INFO
If the provided rate is a float number, Burst will be treated as the rounded down value of the rate.
Custom Configuration
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| config := middleware.RateLimiterConfig{
Skipper: middleware.DefaultSkipper,
Store: middleware.NewRateLimiterMemoryStoreWithConfig(
middleware.RateLimiterMemoryStoreConfig{Rate: 10, Burst: 30, ExpiresIn: 3 * time.Minute},
),
IdentifierExtractor: func(ctx echo.Context) (string, error) {
id := ctx.RealIP()
return id, nil
},
ErrorHandler: func(context echo.Context, err error) error {
return context.JSON(http.StatusForbidden, nil)
},
DenyHandler: func(context echo.Context, identifier string,err error) error {
return context.JSON(http.StatusTooManyRequests, nil)
},
}
e.Use(middleware.RateLimiterWithConfig(config))
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Errors
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| var (
// ErrRateLimitExceeded denotes an error raised when rate limit is exceeded
ErrRateLimitExceeded = echo.NewHTTPError(http.StatusTooManyRequests, "rate limit exceeded")
// ErrExtractorError denotes an error raised when extractor function is unsuccessful
ErrExtractorError = echo.NewHTTPError(http.StatusForbidden, "error while extracting identifier")
)
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TIP
If you need to implement your own store, be sure to implement the RateLimiterStore interface and pass it to RateLimiterConfig and you’re good to go!
Configuration
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| type RateLimiterConfig struct {
Skipper Skipper
BeforeFunc BeforeFunc
// IdentifierExtractor uses echo.Context to extract the identifier for a visitor
IdentifierExtractor Extractor
// Store defines a store for the rate limiter
Store RateLimiterStore
// ErrorHandler provides a handler to be called when IdentifierExtractor returns a non-nil error
ErrorHandler func(context echo.Context, err error) error
// DenyHandler provides a handler to be called when RateLimiter denies access
DenyHandler func(context echo.Context, identifier string, err error) error
}
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Default Configuration
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| // DefaultRateLimiterConfig defines default values for RateLimiterConfig
var DefaultRateLimiterConfig = RateLimiterConfig{
Skipper: DefaultSkipper,
IdentifierExtractor: func(ctx echo.Context) (string, error) {
id := ctx.RealIP()
return id, nil
},
ErrorHandler: func(context echo.Context, err error) error {
return &echo.HTTPError{
Code: ErrExtractorError.Code,
Message: ErrExtractorError.Message,
Internal: err,
}
},
DenyHandler: func(context echo.Context, identifier string, err error) error {
return &echo.HTTPError{
Code: ErrRateLimitExceeded.Code,
Message: ErrRateLimitExceeded.Message,
Internal: err,
}
},
}
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